Part of the host defense system of polymorphonuclear leukocytes. It is responsible for microbicidal activity against a wide range of organisms. In the stimulated PMN, MPO catalyzes the production of hypohalous acids, primarily hypochlorous acid in physiologic situations, and other toxic intermediates that greatly enhance PMN microbicidal activity. Homodimer; disulfide-linked. Each monomer consists of a light and a heavy chain. Belongs to the peroxidase family. XPO subfamily. 3 isoforms of the human protein are produced by alternative splicing. Note: This description may include information from UniProtKB.
Molecular Function: heparin binding; peroxidase activity; metal ion binding; heme binding; chromatin binding
Biological Process: response to food; respiratory burst during defense response; removal of superoxide radicals; response to mechanical stimulus; hydrogen peroxide catabolic process; response to lipopolysaccharide; defense response; response to yeast; response to oxidative stress; defense response to fungus; negative regulation of apoptosis; aging
SS: The number of records in which this modification site was determined using site-specific methods. SS methods include amino acid sequencing, site-directed mutagenesis, modification site-specific antibodies, specific MS strategies, etc.